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Our future, our universe, and other weighty topics

Wednesday, February 19, 2014

Could Another Civilized Species Have Arisen on Earth Before Humanity?

A
fascinating question to consider is: could some other civilized
species have appeared on our planet long before the current race of
humans appeared? I refer to the possibility that civilized
intelligent life may have arisen on this planet many millions of
years ago, such as 10 million years ago, 20 millions years ago, or 30
million years ago.

Most
people will immediately dismiss such a possibility, using reasoning
such as this: Of course, mankind must be the first civilized
species to have appeared on our planet. If there had been some
previous civilized species, they would have left many traces of their
existence which we would have detected long ago.

Such
an argument at first seems very powerful, but it is by no means
conclusive, for several reasons I will now list.

Evidence
of a previous civilization might have been slowly wiped out by eons of
erosion, decay, biological processes, and previous geological
upheavals. Life After People was a fascinating recent
television series that dealt with the question of how soon the
structures of human civilization would break down and disintegrate if
man were to suddenly disappear. The answer often given by the series
was: surprisingly soon. This television series was constantly stating
that large human structures such as skyscrapers and bridges will
break down and crumble over centuries or thousands of years, if there
is no one around to maintain them. A simple example is a bridge. Given a
few centuries with no maintenance, sunlight will cause paint on the
bridge to flake and peel, rust will cause the steel to weaken, and
the bridge will then collapse. Another example is roads. Given many
years of no maintenance, and many years of freezing temperatures,
cracks can form in roads, which winter ice will then widen. Given
thousands of years with no maintenance, the road will disintegrate.

A rusting remnant of a vanished civilization

Then
there are long-term geological processes, which tend to break down
and cover up existing structures. Examples are earthquakes, glaciers,
sedimentation, volcanoes, asteroid collisions, flooding, and
continental drift. Acting over millions of years, such processes may
have completely buried evidence of a civilized species that may have
existed before our species.

But
wouldn't there be many fossils of such a species, if it had existed?
Not if the species buried its dead without coffins. When bodies are
buried without coffins, the bones will normally disintegrate within a
few thousand years. It usually requires a freak geological
occurrence (such as being surrounded by tar or amber) for a bone to
be preserved for millions of year.

A
previous civilized species on our planet may have become extinct
before it became industrialized. If you think about the
possibility of a civilized species existing on our planet long before
the current race of humans, you may think of it having all the
trappings of modern industrial civilization. But a civilized species
could have arisen on this planet millions of years ago, and become
extinct long before reaching the industrial age. Wars, plagues,
natural disasters or climate change (such as the onset of an ice age)
may have made such a civilized species extinct. If a civilization perished
long before reaching the industrial age, it might have left
relatively few traces of itself. Cultures such as the ancient Romans
and the Egyptians (with their tendency towards gigantic engineering
projects) are less common than cultures which leave smaller traces of
their existence.

Evidence
of a previous civilization may have been quickly wiped out by a
planet-wide war or natural catastrophe. There are several
possibilities for a planet-wide catastrophe that could have entirely
wiped out traces of a previous civilized species. One is a global
nuclear war. Imagine nuclear war involving the explosion of, say,
50,000 200-megaton bombs. That might have been sufficient to
instantly remove almost all traces of a previous civilized species.
If such an event had occurred millions of years ago, we might have no
evidence of it today. Another possibility is that an asteroid might have struck
the planet, causing a planet-wide upheaval that buried all traces of
a previous civilized species. Another possibility is a gigantic
volcanic eruption like the one that supposedly occurred out of
Yellowstone Park in the United States about 640,000 years ago, burying land 1000 miles away in ten feet of ash. If
there had been a particularly bad eruption millions of years ago, it
might have buried all evidence of a previous civilization under many
meters of dust and ash.

A
previous civilized species on our planet may have been wiped out by
interstellar visitors, who then removed all traces of it.
One very unlikely but interesting possibility is that visitors from
another planet may have wiped out a previous civilized species on our
planet, and then removed all traces of it. Imagine if millions of
years ago some civilized species had arisen on our planet. Such a
species may have received interstellar visitors who judged it very
harshly. The interstellar visitors may have thought that the
civilization on Earth was too evil or too stupid or too much of a
threat. The interstellar visitors might then have completely
destroyed the civilized species on our planet, and wiped out all
traces of it (which could have been done through the use of robots).
Such visitors may have thought: “This species is an evolutionary
failure, so let's get rid of it and all of its works – we'll clean
the slate, and give this planet another chance to produce an
intelligent species.”

A
previous civilized species on our planet may have migrated to
somewhere else, and removed all traces of its earthly existence.
Imagine if a civilized species had arisen millions of years ago, and
had developed interstellar travel. Such a species might have migrated
to other planets. But surely, one may say, such a species would have
left behind many monuments on our planet, to commemorate its previous
existence on our planet. This would not necessarily be true, however.
If such a species were to evolve to some higher state of existence,
it might look back with contempt at its original state when it
existed on only one planet, thinking of such a state as being utterly
primitive. Such a species might have no interest in preserving the
monuments of its younger days. Just as you might throw out a
scrapbook of your elementary school achievements, a species that had
reached some interstellar level might want to erase all evidence of
its youthful existence on our planet, and restore Earth to a purely
natural state. Thousands of years after developing interstellar
travel, such a species might have developed some refined new standard
of beauty for architecture, and might then have regarded all of the
buildings it had erected on our planet as primitive and ugly, no more
worthy of preservation than some grass huts built by a primitive
tribe. Such a species might then have decided to remove all of the
traces it had left on our planet, and to restore the planet to its
natural beauty, leaving it as a kind of giant park.

We
probably are the first civilized species to arise on this planet, but
in light of all of these possibilities (and others that can be
imagined), we really can't be sure whether civilization first arose
on our planet several thousand years ago or millions of years ago.

Copyright Notice

All posts on this blog are authored by Mark Mahin, and are protected by copyright. Copyright 2013-2014 by Mark Mahin. All rights reserved. Any resemblance between any fictional character and any real person is purely coincidental.